Boiler feed system



D80 2, 1941 R. B. sTEPHENsoN 2,264,599

BOLLER FEED SYSTEM A Filed March 2, 1940 5 Sheets-Sheet l /JTENTOR Aaa/pb 5, elp/venson l ATTORNEY Dec. 2, 1941. R. B. sTEPHl-:NsON

BOILER FEED SYSTEM Filed March 2, 1940 3 Sheets-Sheet 2 lNvENToR v a/ph epbennn ATTORNEY Dwz, 1941.

R. B. STEPHENSON BOILER FEED SYSTEM 5 Sheet s-Sheet 3' Filed March 2, 1940 FIE Q Fl IS Patentecl Dec. 2, 1941 ,reiste @FMC BOILER FEED SYSTEM Ralph B. Stephenson, Oakland, Calif. Application March 2, 1940, Serial No. 321,867

5 Claims. (Cl. 122-457) My invention is concerned generally with boiler feed systems and relates more particularly to an improved system of the above character having means for returning condensate to the boiler and for supplying make-up Water thereto as commonly employed in systems such as laundries where a number of appliances are operated by steam.

It is a general object of the invention to provide an improved boiler feed and return apparatus for supplying condensate and make-up water to the boiler.

Another object of the invention is to provide an improved feed system for boilers wherein the make-up Water is preheated before being introduced into the boiler.

Another object of the invention is to provide an apparatus of the character referred to above wherein the respective means for feeding makeup water and for feeding condensate to the boiler are placed in heat conducting relationship and arranged for cooperative control in feeding to the boiler to replenish the supply Aof water therein.

Another object of my invention is to provide an improved control system for the feeding of condensate and make-up water in boiler systems.

Other objects and advantages will appear from the following description of certain preferred embodiments of the invention, as illustrated in the accompanying drawings, in which:

Figure 1 is a schematic view illustrating a boiler system embodying my invention.

Figure 2 is a longitudinal vertical sectional view of the tank construction for supplying condensate and make-up water to the boiler..

Figure 3 is an end elevation of the tank construction shoWn in Figure 2.

Figure 4 is a view illustrating a modified construction of a tank incorporating the invention, the view being taken in longitudinal, sectional elevation.

Figure 5 is an end elevational View of the tank shown in Figure 4.

Figure 6 is a wiring diagram of the system cient make-up water to maintain the desired amount of water and steam in the system, Figure l illustrates more or less schematically a system embodying my invention, wherein the steam supply boiler is indicated at A. For collecting the return condensate a closed tank B is provided, preferably below'the level of the oor surface. Also a tank construction of special character is provided including a condensate C and a make-up tank D. v

The condensate reservoir B may have associated therewith a plurality of :intake pipes lil leading from the various appliances in use and a discharge pipe Ilv which extends into the tank C and has its opening adjacent the bottom thereof.

t A check valve l2 is provided in the pipe `Il to prevent return of water through the pipe l! to the reservoir B.

The boiler A is provided with a feed pipe i3 leading from the tank C and having a check valve l incorporated therein. From the boiler A a steam feed pipe l extends to the tank construction C-D in a manner hereinafter described. Pipe l is provided with an adjustable valve Il therein to control the flow of steam, and a magnetic steam valve i3, referred to more particularly hereinafter.

To facilitate pre-heating of the make-up water in the tank D aswell as to provide a compact and economical construction, the make-up tank D is preferably mounted within the condensate tank C. For this purpose the tank D (Fig. 2) is made with one end closed and with a flange 2i at its other end, suitably secured to an inwardly extending end flange 22 of the tank C, and secured thereto by suitabie fastening screws with a sealing gasket interposed. To close the flanged end of the tank D a cover plate 2d is secured to the flanged end 22 of the tank C by means of suitable fastening screws 2S with the flanges 2l and 22 separating the tanks C and D. It is seen, therefore, that the tank D is mounted to provide direct heat exchange relationship of its-content with the content of the tank C whereby the respective waters Vin the tanks will tend to have their temperatures equalized.

Means are provided for supplying steam to the tanks C and D simultaneously to effect pre-heating of the contents thereof as Well as to cause the pressures therein to be equalized with the boiler pressure to effect feeding of water to the boiler in a manner hereinafter described.

As seen in Figure 3, steam feed pipe Hi has two branches 3| and 32 beyond valve I8. Branch 3| extends upwardly and then projects through plate 24 into the upper portion of tank D and is provided with a series of openings on the upper side thereof. Branch 32 of pipe I6 is connected by T coupling 33 with pipe 34 also extending into tank D but not opening into the tank.

A check valve 36 is provided in branch 32 of pipe I 6. Within tank D pipe 34 is provided with an imperforate portion 34a of zigzag form. Pipe 34 also extends through the end wall of tank D and has a spiral portion 34b within tank C and disposed around tank D with its discharge end 34o opening into the upper portion of the tank C above the highest level of the water therein.

From the above description it is seen that respective pipes 3| and 34 provide means for introducing steam into the respective tanks D and C, while pipe 34 additionally acts to pre-heat the water in the tank D as well as the water in the tank C, thereby promoting a desirable high temperature of the Water before it is returned to the boiler through the pipe I3, in a manner later described.

To introduce make-up water into the tank D a supply pipe 4I is provided having an adjustable valve 42 and a check valve 43 therein and leads to a pipe 44 extending into the tank D adjacent the lower portion thereof. .Pipe 4I may be connected to a suitable source of water supply such as a pressure system or a gravity feed tank. The pipes 4| and 44 are connected by a T coupling which is also connected with a discharge pipe 46 extending from the tank D and opening into the tank C. Check valve 41 is provided in pipe 46 to prevent flow of Water from the tank C to the tank D but to permit iiow from the tank D to the tank C.

To provide for venting i the tanks C and D as a preliminary to a iilling operation, a vent pipe 5| is provided (Figs. 2 and 3) having a magnetic control valve 52 associated therewith. Pipe 5I is placed in communication with pipe 34 by T coupling 33. The vent pipe 5I is also connected with the pipe 3| for the tank D by means of inclined pipe 53 connected between pipes 5| and 3| to provide an aspirating action upon discharge of steam through the pipe 5 I In order to control alternative operation of the magnetic steam feed valve I8 and the magnetic venting valve 52, an operating circuit is provided therefor, together with a control circuit for selectively controlling the operating circuit.

A suitable form of such circuit is illustrated schematically in Figure 1, and more clearly in Figure 6, wherein the operating circuit is shown as including leads 56 and 51 from a suitable source of 110 volt A. C. current. Lead 51 may be connected directly to valves I8 and 52, while lead 56 may be selectively connected thereto by magnetic relay 58 from which leads 59 and 6U extend to the magnetic control valves I8 and 52 respectively. The magnetic relay 58 may have its armature normally positioned to close the circuit through the lead 66 whereby the vent valve 52 is normally energized, and to have the armature of the relay 58 upon energization thereof open the circuit through the lead 60 and close the circuit through the lead 59 to the magnetic steam valve I8. The magnetic relay 58 is energized from the control circuit.

The control circuit may include a suitable transformer 6I suitably connected to theleads 56 and 51 of the 110 volt current supply to provide an output of say 24 volts for control purposes. One lead 62 from the transformer 6I may be grounded. The other lead 63 from the transformer 6| is connected in parallel to the solenoid of the relay 58 and the solenoid of a magnetic relay 64 and thence through respective leads 65 and 66 to electrodes 61 and 68 of conventional construction which are disposed in tanks C and D respectively to contact and be grounded with the water when it reaches a desired upper level in the respective tanks. The magnetic relay 64, when energized, controls closing of a circuit through lead 69 to electrode 1I which is opened when the water falls below the desired low level in the tank C. Electrode 1I may be mounted in the lower portion of a sight glass 12 associated with tank C. If desired, a pilot light 13 may be placed in the circuit to indicate when the machine is discharging.

The above circuit is merely illustrative and any other suitable control circuit may be provided wherein the solenoids of the magnetic vent valve 52 and the magnetic steam valve are energized alternatively and controlled so that the steam valve will be maintained open after the level of water during iilling of the tanks has reached either of electrodes 61 or 68 until the water level in the tank C has receded below the level of electrode 1I. Also the control must be such that the vent valve will be opened when the water recedes below the level of the electrode 1I and will be maintained open until the water level in one of tanks C and D reaches the electrode 61 or the electrode 68, respectively.

The operation may be briefly summarized as follows: when the water reaches the level of the electrode 61 in the tank C or the electrode 68 in tank D, the steam valve is opened so that the water in the tanks C and D is pre-heated to a desired temperature. The feed o the steam and the feed of the water is controlled so that when the desired level of water is obtained and the desired temperature is obtained, the pressure within the tanks C and D will be equalized with the pressure in the boiler, so that a flow of water starts through the feed pipe I3 to the boiler.

When the receding level of the water in the tank C reaches the level of the water in tank D, a flow of water by gravity will occur from the tank D to tank C through the pipes 44, 46 past the check valve 41, so that during subsequent operations the water in both tanks C and D flows to the boiler. This operation continues until the water level in tank C recedes below the electrode 1I when the circuit to the steam valve I8 will be interrupted and the circuit for the magnetic vent valve 52 will be enabled.

When the vent valve 52 is opened steam is discharged frorn the tank C through the pipe 34 and vent pipe 5|. The rapid passage of steam through the pipe 5| provides an aspirating action in the pipe 53 to cause a vacuum pull on the inner tank D to vent the steam from such inner tank. In this way both tanks C and D have their pressure relieved so that a ow of condensate can commence from the tank B through the pipe II and past check valve I2 into tank C, and so that make-up water will flow through the pipe 4| into the tank D.

During the filling operation, the vent valve 52 remains open until the water rises in tank C to ground the electrode 61, or in tank D to ground the electrode 68, when the circuit to the vent valve 52 will be interrupted and the circuit enabled for the steam valve I8.

When the steam valve IB is opened steam ows into the tank D through pipe 3| and into the tank C through the pipe 34. Because portion 34a of pipe 34 is within tank D the water in this tank will be preheated and actual steam will not enter the tank C until such time as the temperature of the water in the tank D is brought up to a point so that steam can be transmitted through the portion 34a of pipe 34 and portion 34D to be discharged into the tank C. Also, the higher temperature of the condensate water in tank C aids in heating the make-up water in tank D. In this way the temperature of the water in both tanks C and D is equalized.

Because of the heat conducting relationship between tanks C and D and the fact that steam must enter the tank C by first passing through the portion 34a of pipe 34 within tank D and then the spiral portion 34h within tank C, the water in both tanks C and D must be raised to the desired extent before pressure can be built up in the tank C to cause a iiow of water to the boiler. Also because of the heat conducting relationship, excessive pressures cannot be built up within the tank D prior to the time that flow commences.

The above cycle of operation is repeated periodically in accordance with the regulations of the steam iiow and the water flow as controlled by the adjustable valve l1 at 42, so that the cycle is repeated substantially in accordance with boiler requirements to maintain an adequate supply of water therein.

Figures 4 and 5 illustrate a modified construction wherein the tank C, shown in Figure 2, may be employed without the inner tank D when a single Water feed is desired. Similar parts are numbered similarly in Figures 2 and 4.

Referring to Figure 4, the tank C is provided with condensate inlet pipe H and with discharge pipe I3. A steam inlet pipe 34 is provided which is mounted in the cover plate 24 and is connected directly to spiral portion 34h. Magnetic steam valve I8 is associated with pipe 34, which is also connected to vent pipe l having magnetic vent valve 52 therein.

The operation of the device shown in Figure 4 is similar to that described except that the tank C can be used only for feeding make-up water or for returned condensate water.

I claim:

1. In a boiler feed and return system, a tank for receiving condensate returned from the system, a second tank for receiving make-up water, said tanks being disposed in direct heat conducting relation to provide for heating of make-up water by said returned condensate water and means for feeding said make-up Water into said condensate tank and for permitting a simultaneous discharging operation of said tanks.

2. In a boiler feed and return system, a tank for receiving condensate returned from the system, a second tank for receiving make-up water, said tanks being disposed in direct heat conducting relation to provide for heating of makeup Water by said return condensate, a heating pipe extending first into said make-up tank and then into said return tank, and means for supplying steam to said pipe whereby to equalize pressure in said rst named tank with thev boiler pressure.

3. In a boiler feed and return system having a boiler and a reservoir for condensed steam used in the system, a condensate return tank, means for feeding condensate from said reservoir to said tank, a feed pipe extending from said tank to said boiler, a make-up water tank disposed in heat conducting relationship with said condensate feed tank, means for simultaneously supplying steam from said boiler to both said tanks, and means for simultaneously venting both of said tanks.

4. In a boiler feed and return system having a boiler and a reservoir for condensed steam used in the system, a condensate return tank, means Y for feeding condensate from said reservoir to y said tank, a feed pipe extending from said tank to said boiler, a make-up water tank disposed in heat conducting relationship with said condensate feed tank, means for simultaneously supplying steam from said boiler to both said tanks, means for simultaneously venting both of said tanks, and control means for placing said'steam supplying means and said venting means in operation alternatively.

5. In a boiler feed and return system having a means for causing opening of said steam supplying means and closing of said venting means when the water level in either of said tanks rises to a predetermined extent and for maintaining said steam supplying means operative until the water level in one of said tanks has receded to a I predetermined extent.

RALPH B. STEPHENSON. 

